This article shows the difference between the default preferences of Firefox 146.0 beta 3 and Firefox 145.0. The diff table below is generated using my small script firefox-prefjs-surveyer.

Preference difference
PrefFirefox 146.0 beta 3Firefox 145.0
app.normandy.test-prefs.bool undefined false
app.normandy.test-prefs.integer undefined 0
app.normandy.test-prefs.string undefined
app.releaseNotesURL https://www.mozilla.org/%LOCALE%/firefox/%VERSION%/releasenotes/?utm_source=firefox-browser&utm_medium=firefox-desktop&utm_campaign=whatsnew https://www.mozilla.org/%LOCALE%/firefox/%VERSION%beta/releasenotes/?utm_source=firefox-browser&utm_medium=firefox-desktop&utm_campaign=whatsnew
app.releaseNotesURL.aboutDialog https://www.mozilla.org/%LOCALE%/firefox/%VERSION%/releasenotes/?utm_source=firefox-browser&utm_medium=firefox-desktop&utm_campaign=about-dialog https://www.mozilla.org/%LOCALE%/firefox/%VERSION%beta/releasenotes/?utm_source=firefox-browser&utm_medium=firefox-desktop&utm_campaign=about-dialog
app.update.channel release beta
app.update.url.details https://www.mozilla.org/%LOCALE%/firefox/notes https://www.mozilla.org/%LOCALE%/firefox/beta/notes
app.update.url.manual https://www.mozilla.org/%LOCALE%/firefox/new?reason=manual-update https://www.mozilla.org/%LOCALE%/firefox/beta?reason=manual-update
browser.backup.tab-flush-timeout undefined 5000
browser.contentblocking.features.strict tp,tpPrivate,cookieBehavior5,cookieBehaviorPBM5,cryptoTP,fp,stp,emailTP,emailTPPrivate,-consentmanagerSkip,-consentmanagerSkipPrivate,lvl2,rp,rpTop,ocsp,qps,qpsPBM,fpp,fppPrivate,btp tp,tpPrivate,cookieBehavior5,cookieBehaviorPBM5,cryptoTP,fp,stp,emailTP,emailTPPrivate,-consentmanagerSkip,-consentmanagerSkipPrivate,lvl2,rp,rpTop,ocsp,qps,qpsPBM,fpp,fppPrivate,btp,lna
browser.ipProtection.added undefined false
browser.ipProtection.autoStartEnabled undefined false
browser.ipProtection.autoStartPrivateEnabled undefined false
browser.ipProtection.domainInclusions undefined
browser.ipProtection.panelOpenCount undefined 0
browser.menu.showCharacterEncoding chrome://browser/locale/browser.properties undefined
browser.migrate.ie.enabled true false
browser.ml.linkPreview.enabled false true
browser.ml.linkPreview.noKeyPointsRegions AD,AT,BE,BG,CH,CY,CZ,DE,DK,EE,ES,FI,FR,GR,HR,HU,IE,IS,IT,LI,LT,LU,LV,MT,NL,NO,PL,PT,RO,SE,SI,SK
browser.ml.linkPreview.supportedLocales undefined en
browser.newtabpage.activity-stream.discoverystream.attribution.enabled undefined false
browser.newtabpage.activity-stream.discoverystream.contextualContent.enabled false undefined
browser.newtabpage.activity-stream.discoverystream.contextualContent.fakespot.ctaCopy undefined
browser.newtabpage.activity-stream.discoverystream.contextualContent.fakespot.ctaUrl undefined
browser.newtabpage.activity-stream.discoverystream.contextualContent.fakespot.defaultCategoryTitle undefined
browser.newtabpage.activity-stream.discoverystream.contextualContent.fakespot.enabled true undefined
browser.newtabpage.activity-stream.discoverystream.contextualContent.fakespot.footerCopy undefined
browser.newtabpage.activity-stream.discoverystream.contextualContent.feeds need_to_know, fakespot undefined
browser.newtabpage.activity-stream.discoverystream.contextualContent.listFeedTitle undefined
browser.newtabpage.activity-stream.discoverystream.contextualContent.locale-content-config en-US,en-GB,en-CA,de undefined
browser.newtabpage.activity-stream.discoverystream.contextualContent.region-content-config undefined
browser.newtabpage.activity-stream.discoverystream.contextualContent.selectedFeed need_to_know undefined
browser.newtabpage.activity-stream.discoverystream.sections.region-content-config US
browser.newtabpage.activity-stream.discoverystream.thumbsUpDown.region-thumbs-config US US, CA
browser.newtabpage.activity-stream.feeds.newtabattributionfeed undefined true
browser.newtabpage.activity-stream.support.url https://support.mozilla.org/1/firefox/145.0/Linux/en-US/new-tab https://support.mozilla.org/1/firefox/146.0/Linux/en-US/new-tab
browser.newtabpage.activity-stream.system.showSponsoredCheckboxes true undefined
browser.newtabpage.activity-stream.telemetry.ut.events false true
browser.newtabpage.activity-stream.weather.optInDisplayed false true
browser.newtabpage.activity-stream.weather.staticData.enabled false true
browser.preferences.experimental true undefined
browser.safebrowsing.provider.google5.lists goog-phish-proto,googpub-phish-proto,goog-malware-proto,goog-unwanted-proto,goog-harmful-proto goog-badbinurl-proto,goog-downloadwhite-proto,goog-phish-proto,googpub-phish-proto,goog-malware-proto,goog-unwanted-proto,goog-harmful-proto
browser.search.widget.new undefined false
browser.sessionstore.log.appender.file.logOnSuccess false true
browser.sessionstore.loglevel Warn Debug
browser.tabs.dragDrop.multiselectStacking undefined false
browser.tabs.notes.enabled undefined false
browser.tabs.splitView.enabled undefined false
browser.theme.forced-colors-override.enabled undefined true
browser.urlbar.flightStatus.featureGate undefined false
browser.urlbar.quicksuggest.online.available undefined false
browser.urlbar.quicksuggest.settingsUi 0 1
browser.urlbar.sports.featureGate undefined false
browser.urlbar.suggest.quicksuggest.all undefined false
browser.urlbar.suggest.sports undefined true
browser.urlbar.update2.engineAliasRefresh true undefined
devtools.inspector.inactive.css.enabled true undefined
dom.event.keypress.key.allow_lone_surrogate true false
dom.events.script_execute.enabled false undefined
dom.input.showPicker_datalist.enabled undefined true
dom.navigation.webidl.enabled false true
dom.security.trusted_types.enabled false true
dom.security.unexpected_system_load_telemetry_enabled false true
dom.webgpu.enabled false true
dom.webgpu.service-workers.enabled false true
dom.workers.importScripts.enforceStrictMimeType true undefined
dom.workers.throttling.enabled false true
extensions.webcompat-reporter.enabled false true
font.language.group chrome://global/locale/intl.properties undefined
font.size.inflation.disabledInMasterProcess false undefined
gfx.canvas.accelerated.max-snapshot-pbo-memory undefined 67108864
gfx.canvas.remote false undefined
gfx.canvas.remote.allow-in-parent false undefined
gfx.canvas.remote.worker-threads 0 undefined
gfx.direct2d.disabled true undefined
gfx.direct2d.force-enabled false undefined
gfx.direct2d.target-independent-rasterization.disabled false undefined
gfx.webrender.debug.external-composite-borders undefined false
gfx.webrender.precise-conic-gradients false true
gfx.webrender.precise-conic-gradients-swgl false true
intl.accept_languages chrome://global/locale/intl.properties und
intl.ellipsis chrome://global-platform/locale/intl.properties undefined
intl.menuitems.alwaysappendaccesskeys chrome://global/locale/intl.properties undefined
intl.menuitems.insertseparatorbeforeaccesskeys chrome://global/locale/intl.properties undefined
javascript.options.experimental.json_parse_with_source true undefined
javascript.options.experimental.regexp_duplicate_named_groups true undefined
javascript.options.experimental.regexp_modifiers true undefined
javascript.options.experimental.symbols_as_weakmap_keys false true
javascript.options.wasm_relaxed_simd false true
layers.gpu-process.allow-software true undefined
layers.gpu-process.launch-in-background undefined true
layers.gpu-process.startup_timeout_ms 5000 10000
layout.css.at-scope.enabled false true
layout.css.contrast-color.enabled undefined true
layout.css.custom-media.enabled undefined false
layout.css.letter-spacing.model 0 2
layout.css.text-decoration-inset.enabled undefined true
layout.css.text-decoration-trim.enabled false undefined
layout.css.webkit-fill-available.enabled false true
layout.dynamic-reflow-roots.enabled false true
mathml.centered_operators.disabled true undefined
mathml.legacy_mathvariant_attribute.disabled false true
mathml.math_shift.enabled false true
mathml.mathspace_names.disabled false true
mathml.rtl_operator_mirroring.enabled false true
mathml.top_bottom_spacing_for_stretchy_operators.disabled true undefined
mathml.unknown_mrow.enabled true undefined
media.devices.enumerate.legacy.allowlist slack.com,*.slack.com slack.com,*.slack.com,riverside.fm,*.riverside.fm
media.peerconnection.sctp.use_dcsctp false true
media.webrtc.send_mlkem_keyshare false true
media.webrtc.simulcast.vp9.enabled false true
memory.phc.size_kb 1152 16384
network.auth.use_redirect_for_retries false true
network.cache.purge_disable undefined false
network.cache.suspended_writer_delay_ms undefined 5000
network.dns.resolver_shutdown_timeout_ms 2000 5000
network.http.http3.retry_different_ip_family false true
network.http.retry_with_another_half_open false true
network.jar.record_failure_reason false true
network.lna.etp.enabled undefined false
network.lna.local-network-to-localhost.skip-checks undefined true
network.lna.skip-domains undefined
network.lna.websocket.enabled undefined false
network.trr.async_connInfo false true
network.trr.idle_timeout_for_http3_conn 30 400
places.semanticHistory.featureGate false true
privacy.query_stripping.strip_on_share.canDisable true undefined
security.disallow_non_local_systemprincipal_in_tests undefined false
security.qwacs.enable_test_trust_anchors undefined false
security.restrict_to_adults.always undefined false
security.restrict_to_adults.respect_platform undefined false
security.ssl3.ecdhe_ecdsa_aes_128_sha true false
security.ssl3.ecdhe_ecdsa_aes_256_sha true false
services.sync.engine.bookmarks.validation.enabled undefined true
services.sync.engine.passwords.validation.enabled undefined true
services.sync.prefs.sync.browser.discovery.enabled true undefined
termsofuse.firstAcceptedDate undefined 0
toolkit.telemetry.enabled false true
ui.new-webcompat-reporter.send-more-info-link false true
widget.wayland.fractional-scale.enabled false true